Communication protocol broken since 1.7.1

[antonio-fr]

The communication protocol changed unexpectedly in firmware 1.7.1.
Can you share details or point to the relevant documentation of what what changed in the communication protocol of the Trezor (Model One) in the firmware version 1.7.1 ?
There were some changes that break some unmaintained software. Any details about the change can help others developers to make it work again. See : martin-lizner/trezor-ssh-agent#13

This issue is mostly to get help about the issue regarding this other software. One need at least some detailed information about the change of the behavior since the 1.7.1 firmware.

[prusnak]

Versions 1.7.0 and newer communicate via WebUSB protocol (almost identical to HID used previously). Also the vendor_id and product_id has changed to 0x1209 and 0x53C1 respectively to match Trezor Model T (also using WebUSB).

Packet format and everything else hasn't changed at all.

[antonio-fr]

Since 1.7 broke retro-compatibility of the apps using a Trezor One, even the vendor ID changed, I did a new fork of this firmware dedicated to maintain HID and full retro-compatibility about the USB link.
https://github.com/antonio-fr/trezor-mcu-hid